My wife and I did this fantastic trip a couple of years back, the train shown is preceeded by a converted railbus with a similar arrangement of roof riding, but these are actual seats angled at 45 degrees to the forward, absolute luxury by comparison. The railbus is owned and operated by Metropolitan Touring of Ecuador. We were fortunate to have a cloudless August day for our trip, and no derailments! They pull you up after about an hour at one of the old stations now a restaurant,for a full breakfast, the railbus just sits there till you're done. You pull up again at Alausi for refreshments before decending the zig-zags down the nose, and then back up again after turning on the wye. The train was shadowed the whole trip by security agents in 4WD's carrying shot guns, they met the train at every crossing exchanging waives with the crew and eventually the passengers when we realised what was going on! By the time we had got back up the nose to Alausi the regular train had arrived much to the pleasure of the locals who were doing a roaring trade in snacks (and occasional stuffed Lamas!)for the tourists.
We also did the Avenue of Volcanes section just out of Quito on an identicle railbus, but the route is fragmented after an El Nino storm some time ago. We have read recently that work has been going on in an attempt to restore the whole route from Quito right the way back to Guayaquil. Harold.